Hey,
I've been running the same issue, but my case is even more strange ;
Opening App and Browser Control via Research or command lines will just crash at boot up, so something missing.
No updates, either by Windows Updates or by forcing a Signatures Update via command lines.
C:\Windows\System32\SecurityHealth is empty for me. No App.
Regedit showed that HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender Security Center is missing (Windows Defender Security Center is missing), which implies \App and Browser protection subfolder is missing as well.
Resetting Windows Security App crashes when the command initialize (Get-AppxPackage *Microsoft.Windows.SecHealthUI* | Reset-AppxPackage) with no errors. Using the reset feature over Installed App on Windows Security seem/pretend to work as it doesn't say an error and shows completion, but has no effect.
Installing a previous Windows Security App version do "work" (as it doesn't fail during the process and version has successfully changed when checking manually) but fails.
I tried installing ver 1000.22621.1.0 package.
What's even funnier? This is literally a fresh windows installation! I reinstalled Windows after a Hard Disk rewriting and installing Windows 11 using the Download Windows feature in the Reset Windows menu, so I can't make it more fresh, beside using an external drive..
Any suggestions I did not tried yet? Besides performing a Windows Installation again :(